It is proposed to continue studies on the biosynthesis of bacterial glycogen, particularly the various regulatory phenomena (allosteric and genetic) associated with the various glycogen biosynthetic enzymes. Physical and chemical characterization and comparison of homogenous preparations of the E. coli B ADPglucose pyrophosphorylase and ADPglucose pyrophoshorylases from E. coli B glycogen mutants that are altered in their allosteric properties are intended. Immunological comparison of the ADPglucose pyrophosphorylases of the enteric organism is also contemplated. The continued characterization of the E. coli B glycogen synthase is planned with respect to reaction mechanism and the various amino acid residues involved in catalysis. Branching enzyme of E. coli B will be purified and characterized and its interaction with glycogen synthase studied. Studies on the genetic regulation of glycogen synthesis in E. coli B and Salmonella typhimurium Lt-2 will be continued with the objective of determining the location of the two different regulatory genes. BIBLIOGRAPHIC REFERENCES: Steiner, K. E. and J. Preiss (1977). Biosynthesis of bacterial glycogen. Genetic and allosteric regulation of glycogen biosynthesis in Salmonella typhimurium LT-2. J. Bacteriol. 129, 246-253. Preiss, J. (1977). Regulation of ADPglucose pyrophosphorylase. In: Advances in Enzymology (A. Meister, ed.), J. Wiley and Sons, in Press.